Machine Learning with R Cookbook - Second Edition

How to do it...

Perform the following steps to see subsetting. It is assumed that the DataFrame d and matrix m exist from the previous exercise:

> d$No   # Slice the column 
Output: 
[1] 1 2 3 
> d$Name  # Slice the column 
Output: 
[1] A B C 
> d$Name[1] 
Output: 
[1] A 
> d[2,]  # get Row 
Output: 
      No       Name   Attendance2    2          B          FALSE 
> temp = c(1:100) # Creates a vector of 100 elements from 1 to 100 
> temp[14:16]  # Part from vector 
Output: 
[1] 14 15 16 
> m[,2]    # To access second column from matrix m 
Output: 
[1] 4 5 6 
> m[3,]  # To access third row from matrix m 
Output: 
[1] 3 6 
> m[2,1]  # To access single element from matrix m 
Output: 
[1] 2 
> m[c(1,3), c(2)] # Access [1,2] and [3,2] 
Output: 
[1] 4 6